New Evidence of Gravitational Wave Background Permeating All of Spacetime:
The results of a comprehensive search for a background of ultra-low frequency gravitational waves has been announced by an international team of astronomers including scientists from the Institute for Gravitational Wave Astronomy at the University of Birmingham.
These light-year-scale ripples, a consequence of Einstein’s theory of general relativity, permeate all of spacetime and could originate from mergers of the most massive black holes in the Universe or from events occurring soon after the formation of the Universe in the Big Bang. Scientists have been searching for definitive evidence of these signals for several decades.
The International Pulsar Timing Array (IPTA), joining the work of several astrophysics collaborations from around the world, recently completed its search for gravitational waves in their most recent official data release, known as Data Release 2 (DR2).
This data set consists of precision timing data from 65 millisecond pulsars – stellar remnants which spin hundreds of times per second, sweeping narrow beams of radio waves that appear as pulses due to the spinning – obtained by combining the independent data sets from the IPTA’s three founding members: The European Pulsar Timing Array (EPTA), the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), and the Parkes Pulsar Timing Array in Australia (PPTA).
These combined data reveal strong evidence for an ultra-low frequency signal detected by many of the pulsars in the combined data. The characteristics of this common-among-pulsars signal are in broad agreement with those expected from a gravitational wave “background.”
The gravitational wave background is formed by many different overlapping gravitational-wave signals emitted from the cosmic population of supermassive binary black holes (i.e. two supermassive black holes orbiting each other and eventually merging) – similar to background noise from the many overlapping voices in a crowded hall.
This result further strengthens the gradual emergence of similar signals that have been found in the individual data sets of the participating pulsar timing collaborations over the past few years.
Journal Reference:
J Antoniadis, Z Arzoumanian, S Babak, et al. The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background (DOI: 10.1093/mnras/stab3418; arxiv: 2201.03980)
(Score: 0) by Anonymous Coward on Thursday January 13 2022, @06:45PM (3 children)
While some pulsars might spin hundreds of times per second, wouldn't a period of 65 ms correspond to fifteen times per second.
(Score: 3, Informative) by maxwell demon on Thursday January 13 2022, @07:29PM (2 children)
The 65 is the number of microsecond pulsars they took the timing data from.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 3, Interesting) by tizan on Friday January 14 2022, @12:54AM (1 child)
No it is not microseconds.... A millisecond pulsar is usually one that have period between 1 ms to > 10 ms... When it is close to 0.1 s then it is no longer considered a ms pulsar.
so the 65 pulsars with spinning period of the order 1 to 10 ms would be the interpretation
(Score: 2) by maxwell demon on Friday January 14 2022, @07:48AM
Yeah, the micro was a mistake by me. My point was that the number 65 was not counting time units but pulsars.
The Tao of math: The numbers you can count are not the real numbers.
(Score: -1, Offtopic) by Anonymous Coward on Thursday January 13 2022, @07:44PM (1 child)
do not want to encourage the alt-dark crowd, but can a theory begat a fact? /pedant
(Score: 0) by Anonymous Coward on Friday January 14 2022, @02:23AM
i also find it a strange construction
something real that's actually happening was observed by a human
the humans have a theory that describes what they're looking at and allows them to reason about it
it was happening long before there was a human to observe and reason about it, and it will continue regardless of what becomes of the humans